1. Field of the Invention
Embodiments of the present invention relate, in general, to personal wireless networks and more particularly to personal basic service set coordination point handovers in a personal wireless network.
2. Relevant Background
The Institute for Electronic and Electrical Engineers (IEEE) 802.11 standard for wireless networking details specifications and procedures for infrastructure Base Service Set (BSS), Independent BSS, and Mesh BSS in bands lower than 6 GHz. Wi-Fi also details specifications and procedures for peer-to-peer networks. All these networks can cover a large scope (several hundred meters).
IEEE and several organizations continue work to define specifications and procedures for wireless communications in the 60 GHz band. License-free 60 GHz radios have unique characteristics that make them significantly different from traditional 2.4 GHz or 5 GHz license-free radios and from licensed-band millimeter-wave radios. Oxygen attenuates 60 GHz signals. This is unique to the 60 GHz spectrum and limits the distances that 60 GHz links can cover to just about 10 meters. Even in such a distance, to guarantee Medium Access Control (MAC) layer data rate at about 1 Gbps, directional communication between the source station and the destination station is required.
WiGig Alliance (WGA) was established by more than 15 technology leaders within the CE, PC, semiconductor and handheld industries to unify the next generation of wireless products by encouraging the adoption and widespread use of 60 GHz wireless technology worldwide. WGA 60 GHz specification defines a new kind of BSS, referred to as a personal basic service set (PBSS) which is Personal Area Network (PAN) per 60 GHz's radio property. A PBSS is a BSS which forms a self-contained network, includes a PBSS coordination point (PCP), and in which access to a distribution system (DS) is not available. Membership in a PBSS implies that wireless communication with all other members of the PBSS is possible without creating a direct link as in the 802.11 infrastructure BSS under 60 GHz.
An important difference between an independent BSS (IBSS) and the PBSS is that within the PBSS only a single station (STA), namely the PCP, is responsible for beacon frame transmission. Within the IBSS, all STAs are responsible for beacon frame transmission. When compared to the infrastructure BSS, the PBSS does not provide certain distribution system services.
As long as the PCP remains active and capable of managing the BSS, other stations can come and go freely. As they enter, new stations are synchronized with the other stations, and as a STA leaves, it is removed from the PCP's managerial list. However, as the PCP is simply a peer device fulfilling the role of a master controller, it, too, may depart from the network it has itself established. When a PCP leaves the network or becomes incapable of fulfilling the role as the PCP, the PBSS ceases to exist unless the role of the PCP can be handed over to another station within the BSS that is capable and willing to undertake the PCP responsibilities.
Handing over the control and management of the stations within a BSS efficiently and without disrupting the PBSS is one of many challenges that are addressed by one or more embodiments of the present invention.